Bearing-metal alloy



Patented Nov. 20, 1928.

UNITED STATES KARL MULLER AND WILHELM SANDER, F ESSEN, GERMANY:

BEARING-.METAL ALLoY.

No Drawing Application filed September 30 1921,

of lead, percent of antimony and 5 percent.

of tin. For the purpose of avoiding segregation as well as increasingthe degree of hardness, small percentages of copper have been added tothese lead alloys. However the alloys of this type did notshow suchproperties as to render them capable of being employed as fullsubstitutes for the former bearing metals containing percent and more oftin.

Thereafter it has been tried to develop the scribed above are by nomeans lessened, but

desired properties in the alloys mentioned by adding other metals, butowing to the fact that most of the metals will not alloy with lead,these experiments failed because in some cases it was impossible to geta perfect mixing or, in other cases, on cooling the additional metalsseparated out from the alloy. Moreover if one succeeds in introducingsmall amounts of other metals without risk of separation on cooling, thefurther'disadvantage arises that these additions will solidfy attemperatures above the eutectic of lead, antimony and tin, in such a waythat the alloys must pass through a rather large range of solidificationand consequently become pasty on cooling. This fact involves a very highcasting temperature whereby oxidation will be advanced, the easilyoxidizable constituents will be burned off, and the tendency tosegregation will be increased. Besides, when casting such bearingmetals, frequently piping and blisters are formed owing to the largemelting range.

We have found that all the objections pointed out above can be avoided,and that it is possible to obtain in such alloys with a high leadcontent, though containing only a small (say 4 to 5 percent) amount oftin, all those properties to make them fully equivalent substitutes forthe high-grade tin alloys formerly used for bearing metals.

This surprising effect is essentially realized by relatively small (say1 to 3 percent) additions of nickel together with a somewhat smallerquantity of copper. Preferably the copper is introduced in the shape ofcopper phosphide, the phosphorus in this combina Serial No. 504,374, andin Germany October 1, 1920f tion increasing the hardness of the alloy toa certain extent. The phosphorus may in this case be Wholly or partiallyreplaced by arsenic which is known to be equivalent to phosphorus withrespect to the metallurgical action under consideration.

Based on numerous elaborate experiments, the following limits can-bestated for the constituents of alloys which will show the advantagesmentioned abovei about 70 to 75 percent of lead, about 15 to 25 percentof antimony, about 3 to 6 percent of tin, about 1 to 3 percent ofnickel, about 0.6 to 1.5 percent of copper (introduced in form of 0.8 to2.2 percent of copper phosphide) The many advantages of such alloys asdeeven in some respects are increased by wholly or partiallysubstituting cobalt for nickel. Nickel and cobalt are metals of the sametype, closely resembling each other but for the present purposes cobalthas some specific advantages. Such an alloy containing cobalt speciallydifiers from the corresponding nickelalloy, inasmuch as it possesses ahigher degree of plasticity and, consequently, a greater hardeningcapacity without risk of becoming too brittle.

Finally we have found that such alloys as described above, i. e. with avery high lead content and a lower content of antimony and tin, whichare improved by small additions of nickel, or cobalt, together withcopper, will be improved further by introducing relatively very smallquantities ofmetals belonging to the iron or chromium-group, preferablyconjointly with elements of the phosphorusgroup.

By way of example for such an alloy the following composition may bestated: .70 percent of lead, 20 percent of antimony, 5 percent of tin, 2percent of nickel, 1 percent of copper, 0.7 percent of iron, 0.3 percentof manganese, 0.5 percent of phosphorus, 0.5 percent of arsemo.

1. A bearing metal alloy comprising about This bearing metal alloy byreason of its 7 O to 75 percent of lead, about 15 to 25 percent )fantimony, about 3 to 6 percent of tin, about 1 to 3 percent of a'metalof the cobalt type,

1 to 3 percent of cobalt, and about 0.6 to 2 I percent of copper.

3. A bearing metal alloy comprising about 70 to 75 percent of lead,about 15 to 25 percent of antimony, about 3 to 6 percent of tin, about 1to 3 percent of nickel and cobalt together, and about 0.6 to 2 percentof copper.

4. A bearing metal alloy comprising about 70 to 75 percent of lead,about 15 to 25'percent of antimony, about 3 to 6 rcent of tin, about 1to 3 percent of metal of ti: cobalt type, about 0.6 to 2 percent ofcopper and an a preciable amount not exceeding 1 percent of e e'rne'ntsof the phosphorus group.

1 to 3 percent of cobalt, a

5. A bearing metal alloy comprising about 70 to 75 percent of lead,about 15 to 25 percent of antimony, about 3 to 6 percent of tin, aboutout 0.6 to 2 percent of copper, and an appreciable amount not exceeding1 percent of elements of the phosphorus group. v

6. A bearing metal alloy comprising about 70 to 75 percent of lead,about 15 to 25 percent of antimony, about 3 to6 percent of tin, about 1to 3 percent of a metal of, the cobalt type, about 0.6 to 2 percent ofcopper, an appreciable amount not exceeding 1 percent of metals of theiron group, and an appreciable amount not exceeding 1 percent ofelements of the phosphorus group.

In testimony whereof we aflix our signatures.

' DR. KARL MULLER.

DR. WILHELM SANDER.

